package com.rpframework.core.utils;

import org.jetbrains.annotations.NotNull;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * <pre>
 * 生成MD5加密字符串
 * 2014年6月22日
 * </pre>
 **/
public class Md5Utils {

	private static final char[] DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e',
			'f' };
    @NotNull
	public static String md5(String text) {
		MessageDigest msgDigest = null;

		try {
			msgDigest = MessageDigest.getInstance("MD5");
		} catch (NoSuchAlgorithmException e) {
			throw new IllegalStateException("System doesn't support MD5 algorithm.");
		}

		try {
			msgDigest.update(text.getBytes("utf-8"));
		} catch (UnsupportedEncodingException e) {
			throw new IllegalStateException("System doesn't support your  EncodingException.");
		}
		byte[] bytes = msgDigest.digest();
		String md5Str = new String(encodeHex(bytes));
		return md5Str;
	}

	public static char[] encodeHex(byte[] data) {
		int l = data.length;
		char[] out = new char[l << 1];
		for (int i = 0, j = 0; i < l; i++) {
			out[j++] = DIGITS[(0xF0 & data[i]) >>> 4];
			out[j++] = DIGITS[0x0F & data[i]];
		}
		return out;
	}
}
